I found a way here on HN to use uBlock to set Dark Mode and undo the downvote colors. I don't remember who suggested the Dark Mode. This is from "My Filters"

  ycombinator.com##html:style(background-color: #3e3e42 !important)
  ycombinator.com###hnmain:style(background-color: #2E2E31 !important)
  ycombinator.com##.age:style(color: #ccc !important)
  ycombinator.com##.c00:style(color: #ccc !important)
  ycombinator.com##.c5a:style(color: #ccc !important)
  ycombinator.com##.c73:style(color: #ccc !important)
  ycombinator.com##.c82:style(color: #ccc !important)
  ycombinator.com##.c88:style(color: #ccc !important)
  ycombinator.com##.c9c:style(color: #ccc !important)
  ycombinator.com##.cae:style(color: #ccc !important)
  ycombinator.com##.cbe:style(color: #ccc !important)
  ycombinator.com##.cce:style(color: #ccc !important)
  ycombinator.com##.cdd:style(color: #ccc !important)
  ycombinator.com##.comhead > a:style(color: #dedede !important)
  ycombinator.com##.comhead:style(color: #dedede !important)
  ycombinator.com##.hnuser:style(color: #ccc !important)
  ycombinator.com##.subtext > a:link:style(color: #ccc !important)
  ycombinator.com##.subtext > a:style(color: #ccc !important)
  ycombinator.com##.subtext:style(color: #ccc !important)
  ycombinator.com##.title > a:style(color: #dedede !important)
  ycombinator.com##a:link:style(color: #ccc !important)

The .c00 is the default text and the .c5a through .cdd are the 9 shades of gray.